// Copyright (c) 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// This file contains data structures and utility functions used for serializing
// and parsing alternative service header values, common to HTTP/1.1 header
// fields and HTTP/2 and QUIC ALTSVC frames.  See specification at
// https://httpwg.github.io/http-extensions/alt-svc.html.

#ifndef NET_SPDY_SPDY_ALT_SVC_WIRE_FORMAT_H_
#define NET_SPDY_SPDY_ALT_SVC_WIRE_FORMAT_H_

#include <stdint.h>

#include <vector>

#include "base/strings/string_piece.h"
#include "net/base/net_export.h"

namespace net {

namespace test {
    class SpdyAltSvcWireFormatPeer;
} // namespace test

class NET_EXPORT_PRIVATE SpdyAltSvcWireFormat {
public:
    using VersionVector = std::vector<uint16_t>;

    struct NET_EXPORT_PRIVATE AlternativeService {
        std::string protocol_id;
        std::string host;

        // Default is 0: invalid port.
        uint16_t port = 0;
        // Default is one day.
        uint32_t max_age = 86400;
        // Default is empty: unspecified version.
        VersionVector version;

        AlternativeService();
        AlternativeService(const std::string& protocol_id,
            const std::string& host,
            uint16_t port,
            uint32_t max_age,
            VersionVector version);
        AlternativeService(const AlternativeService& other);
        ~AlternativeService();

        bool operator==(const AlternativeService& other) const
        {
            return protocol_id == other.protocol_id && host == other.host && port == other.port && version == other.version && max_age == other.max_age;
        }
    };
    // An empty vector means alternative services should be cleared for given
    // origin.  Note that the wire format for this is the string "clear", not an
    // empty value (which is invalid).
    typedef std::vector<AlternativeService> AlternativeServiceVector;

    friend class test::SpdyAltSvcWireFormatPeer;
    static bool ParseHeaderFieldValue(base::StringPiece value,
        AlternativeServiceVector* altsvc_vector);
    static std::string SerializeHeaderFieldValue(
        const AlternativeServiceVector& altsvc_vector);

private:
    static void SkipWhiteSpace(base::StringPiece::const_iterator* c,
        base::StringPiece::const_iterator end);
    static bool PercentDecode(base::StringPiece::const_iterator c,
        base::StringPiece::const_iterator end,
        std::string* output);
    static bool ParseAltAuthority(base::StringPiece::const_iterator c,
        base::StringPiece::const_iterator end,
        std::string* host,
        uint16_t* port);
    static bool ParsePositiveInteger16(base::StringPiece::const_iterator c,
        base::StringPiece::const_iterator end,
        uint16_t* value);
    static bool ParsePositiveInteger32(base::StringPiece::const_iterator c,
        base::StringPiece::const_iterator end,
        uint32_t* value);
};

} // namespace net

#endif // NET_SPDY_SPDY_ALT_SVC_WIRE_FORMAT_H_
